Valve for external combustion motor

ABSTRACT

The invention relates to an inlet valve of a cylinder wherein expands a pressurized fluid of a piston motor of the kind comprising at least two cylinders inbetween which is provided a combustion chamber at constant pressure wherein the said fluid pressurized in the compressor cylinder is subjected to an increase of pressure. The seat of the inlet valve is fitted so that the latter shall be opened towards the outside of the cylinder, by means of direct control, without pressure compensation, such valve comprising a cooling device substantially provided by a skirt surrounding the valve over at least part of the periphery thereof. The layout of this valve permits to dispense with a system of pressure compensation and assures an excellent cooling of the valve.

United States Patent 191 Van Avermaete 1]. 3,826,081 [451 July 30., 1974 VALVE FOR EXTERNAL COMBUSTION MOTOR [76] Inventor: Gilbert Lucien Van Avermaete, 20

Rue de 1 Europe, B-67 Arlon,

Belgium [22]- Filed: Mar. 28, 1972 [21] Appl. N0.: 238,769

[52] US, Cl 60/39.63, 123/4l.l7, 123/41.85 [51] Int. Cl. F01p 1/08, F02g 3/00 [58] Field of Search 60/3963, 39.6, 39.61,

[56] References Cited UNITED STATES PATENTS I 2,459,447 1/1949 Milliken.. 60/3963 3,577,729 5/l97l Warren 60/39/63 FOREIGN PATENTS OR APPLICATIONS 314,0l8

4/1930 Great Britain l23/4l. l 7

Primary Examiner-Carlton R. Croyle Assistant Examiner-Michael Koczo, Jr.

Attorney, Agent, or Firm-Cushman, Darby &

Cushman i 57 ABSTRACT The invention relates to an-inlet' valve of a cylinder wherein expands a pressurized fiuido'f a piston motor of the kind comprising at least two cylinders inbetween which'is-provided a-combustion' chamber at constant pressure wherein the-said fluid pressurized in the compressor cylinder is subjected to'an increase of pressure. 1 The seat of the inlet valve is fitted so that the latter shall be opened towards the outside of the cylinder, by

means of direct control, without pressure compensation, such valve comprising a cooling device substantially provided by a skirt surrounding the valve over at least part .of the periphery thereof. The layout of this valve permits to dispense with a system of pressure compensation and assures an excellent cooling of the valve.

, ,3 Claims, 3 Drawing Figures VALVE FOR EXTERNAL COMBUSTION MOTOR The present invention relates in particular to an inlet valve of a cylinder wherein expands a pressurized fluid, of a piston motor of the kind comprising at least two cylinders inbetween which is provided a combustion chamber at constant pressure wherein the said fluid, pressurized in the compressor cylinder, is subjected to 5 jection retracts from the said tapered surface, so that an increase of pressure and is expanded in the said cylinder wherein the pressurized fluid is expanded.

The air of the valve according to the invention is to permit dispensing with the system of pressure compensation provided in order to assist the control device of the inlet valve of the cylinder wherein the expansion in the said type of motor takes place, on opening the valve, this compensation system presenting the disadvantage of increasing the inertia of the said valve and of being a source of additional friction.

' For that purpose, according to the invention, the seat of the said inlet valve is fitted so that the latter shall open towards the outside of the cylinder, its control device being direct, without intercalation of a system for compensating the pressures inside the cylinder wherein the fluid expands and in the combustion chamber, the control system of the exhaust cylinder of the latter cylinder being adjusted in such a mannerthat the exhaust valve shall be in the closed position before the piston the flow passage inbetweenthem shall increase very rapidly and permit the cooling fluid to scavenge the periphery of the valve head at the moment when high temperature fluid is admitted to the cylinder.

According to'a particularly advantageous modeof embodiment of the invention, a by-pass is provided in the cooling fluid feed pipe upstream of the said skirt, this by-pass opening in a peripheric recess provided around the valve seat beneath the said skirt, this recess communicating over the whole of its periphery with the high temperature fluid channel, facing the valve head area-not surrounded by the skirt, so that the cooling fluid shall cool the latter area.

The invention has also for its object an inlet valve control device permitting to implement very small inlet quantities while maintaining the lead of admission and of this cylinder reaches its upper dead centre, the fluid fluid expands of a piston motor of the said kind, thiscooling device comprising a feed pipe for pressurized fluid at lower temperature than that of the fluid originating from the combustion chamber, this feed pipe opening close to the valve head.

The air of the cooling device according to the invention is to cool the valve in an efficient manner, particularly by assuring the thorough scavenging by the cooling fluid of the valve portions located in the motor area subject to high temperatures.

For that purpose, according to the invention, the feed pipe for the said fluid opens into a stationary skirt fitted inside the feed pipe for the pressurized fluid at high temperature originating from the combustion chamber and surrounding the valve stem, the edge of the skirt extending to the vicinity of the valve head in order to surround the latter over at least part of the height of its periphery.

According to a mode of embodiment of the invention the inlet valve head is recessed from its face directed towards the insideof the skirt, in order to provide in? side the valve a peripheric chamber of large dimensions communicating with the inside of the skirt fed with pressurized cooling fluid.

According to an advantageous embodiment of the invention the inner wall of the said skirt is inclined, close to the skirt edge, in such a manner as to provide a tapered surface the apex of which is positioned, outside the skirt on the axis of the valve stem, the valve head having, in the portion thereof positioned inside the skirt, a peripheric annular projection extending facing the inclined wall of the skirt in order that, when the valve is closed, the flow passage of the cooling fluid bethe compression constant.

For that purpose, according to the invention, the said control device comprises a system with rotary cams and working lever known by the name of Caprotti system.

The invention has stillfurther for its object a motor comprising either the said inlet valve or the valve cooling device or again the said valve control device.

A particular constructional embodiment of the present invention will now be described, by way ofnon limitative example, with reference to the accompanying drawings, in which: I

FIG.,1 is a diagrammatic view, partially broken away, of an external combustion motor, the cylinder of which, wherein expands the fluid, is provided with an inlet valve according to the invention.

FIG. 2 is an elevational sectional view along the line 11-11 of FIG. 1 showing the said inlet valve in the open position as well as the control device thereof. FIG. 3 is an elevational sectional view along the line III-III of FIG. 1, showing the exhaust valve of the fluid expansion cylinder together with its control device, this valve being shown in the closed position. a In the different Figures, the same numerical references refer to identical elements.

The inlet valve 1 according to the invention and shown on the drawings is for mounting on the cylinder 3 of a piston motor shown in FIG. 1, comprising at least two cylinders 2 and 3 between which is fitted a combustion chamber 4 at constant pressure wherein the pressure of the fluid pressurized in the cylinder 2 is increased for subsequentexpansion in cylinder 3. The seat 5 of the valve is fitted so. that the latter opens towards the outside of cylinder 3. The control device for the valve 1 is direct acting and comprises a system 6 with rotary cams 7 and'8 and working lever 9 known by the name of Caprotti system; a'spring 10 being provided to draw the valve back on to its seat. This method for opening the valve allows to dispensewith the system for compensating the pressures in the cylinder 3, and the chamber 4 which is necessary for motors of the said kind in order to assure the closure of the inlet valve of the cylinder 3, opening to the inside of the cylinder, this valve being biased to remain open on account of the pressure insidethe chamber 4. With the valve according to the invention, it is on opening the valve that the pressure inside the chamber 4 has to be overcome. In order to achieve this object, without compensating system, the control device 11 of the exhaust valve 12 of the cylinder 3 is adjusted so that it shall be in the closed position before piston 13 shall have reached its upper dead centre, the fluid remaining in the cylinder 3 and pressurized by the piston reaching its upper dead centre balancing the pressure applied against the face of the valve biased by the pressurized fluid originating from the chamber 4 and permitting the system 6 to move the valve 1 to the open position, free of strain.

The device for cooling, according to the invention, the inlet valve 1 of cylinder 3 comprises a pressurized fluid feed pipe 14 at alower temperature than that of V the fluid originating from the combustion chamber 4 and opening on the one hand, between the cylinder 2 and the combustion chamber 4, in the'conduit 14' connecting the latter to the cylinder 2 and, on the other hand, close to the head 15 of the valve 1. The feed pipe 14 opens inside a stationary skirt 16 mounted in the feed channel 17 for the pressurized high temperature fluid connecting the chamber 4 to the cylinder 3 and which surrounds the stem 18 of the valve 1, the edge 19 of the skirt extending as far as close to the valve head 15 in order to surround the latter over a portion of the height-of the periphery thereof.

As shown in FIG. 2, the head 15 of the valve 1 is advantageously recessed from its face 20, in order to provide a peripheric chamber 21-of-large dimensions inside the valve, this chamber 21 communicating with the interior of the skirt 16 supplied with pressurized cooling fluid. The wall of skirt 16, close to the edge 19 thereof is inclined to provide a tapered face 22 the apex of which is positioned outside the skirt, on the axis of l the stem 18 of the valve 1, the head 15 of the latter being provided, in the portion thereof positoned inside the skirt, with an annular peripheric projection 23 extending facing the inclined .wall 22 of the skirt 16 in order to restrict as much as possible the passage for the cooling fluid between the valve head and the skirt in direction of the channel 17 for the high temperature fluid when the valve is closed, valve 1 being fitted in such a manner that, on opening thereof, the annular projection 23 shall retract from the said tapered face 22 so that the passage between the latter shall increase very rapidly and permit the cooling fluid to scavenge the periphery of the valve head at the moment when high temperature fluid'is admitted to the cylinder.

According to the invention a by-pass 24 is provided in the cooling fluid feed pipe 14, upstream of the skirt 16, this by-pass 24 opening in a peripheric recess 25 provided around the seat 5 of valve 1, beneath the said skirt, this recess 25 communicating over the whole of the periphery thereof with the high temperature fluid channel 17, facing the valve head area not surrounded by the skirt, in order that the cooling fluid shall cool the latter area.

It is well understood that the invention is not limited to the described embodiment and that many changes may be introduced therein without departing from th scope of the present patent application. 1

I claim:

1. In a piston motor including an expansion cylinder wherein a pressurized fluid expands and a combustion chamber at constant pressure wherein said fluid is subjected to an increase of pressure, a feed channel connected between said combustion chamber .and said expansion cylinder and an inlet valve having a stem and a head mounted in said feed channel for controlling the flow of said pressurized fluid into said expansion cylinder, the improvement which comprises a cooling device for said valve, said cooling device comprising a feed pipe for pressurized cooling fluid at a lower temperature than the temperature of the fluid originating from the combustion chamber and a stationary skirt fitted inside said feed channel and surrounding the stem of said inlet valve and having an edge extending to the vicinity of the inlet valve head in order to surroundthe latter over at least part of the height of its periphery, said feedpipe for pressurized cooling fluid at lower temperaturev opening into the inside of said skirt, said skirt also having a peripheric wall inclined close to said skirt edge in such a manner as to provide .a tapered surface, the apex of which is positioned outside the skirt on the axis of the valve stem, the valve head having, in the portion thereof positioned inside the skirt, a peripheric annular projection extending facing the inclined wall of the skirt in order that, when the valve is closed, the flow passage of the cooling fluid between the valve head and the skirt in the direction of the high temperature fluid channel shall be restricted as much as possible, the valve being fitted in such a manner that, on the opening thereof, the annular projection retracts from the said tapered surface, so that the flow passage in between them shall increase very rapidly and'permit the cooling fluid to scavenge the periphery of the valve head at the moment when high temperature fluid is admitted to the cylinder.

'2. A motor as claimed in claim 1, wherein said inlet valve head is provided with a recess on its face directed towards the inside of the skirt,'in order to provide inside the valve a peripheric chamber of large dimensions communicating with the inside of the skirt fed with pressurized cooling fluid.

3.'A motor as claimed in claim l,'wherein a by-pass is provided in the cooling fluid feed pipe upstream of the said skirt, this by-pass opening in a peripheric recess provided around the inlet valve seat beneath the i said skirt, this recess communicating over the whole of its periphery with the high temperature fluid channel, facing the valve head area not surrounded by the skirt,

so that the cooling fluid shall cool the latter area. 

1. In a piston motor including an expansion cylinder wherein a pressurized fluid expands and a combustion chamber at constant pressure wherein said fluid is subjected to an increase of pressure, a feed channel connected between said combustion chamber and said expansion cylinder and an inlet valve having a stem and a head mounted in said feed channel for controlling the flow of said pressurized fluid into said expansion cylinder, the improvement which comprises a cooling device for said valve, said cooling device comprising a feed pipe for pressurized cooling fluid at a lower temperature than the temperature of the fluid originating from the combustion chamber and a stationary skirt fitted inside said feed channel and surrounding the stem of said inlet valve and having an edge extending to the vicinity of the inlet valve head in order to surround the latter over at least part of the height of its periphery, said feed pipe for pressurized cooling fluid at lower temperature opening into the inside of said skirt, said skirt also having a peripheric wall inclined close to said skirt edge in such a manner as to provide a tapered surface, the apex of which is positioned outside the skirt on the axis of the valve stem, the valve head having, in the portion thereof positioned inside the skirt, a peripheric annular projection extending facing the inclined wall of the skirt in order that, when the valve is closed, the flow passage of the cooling fluid between the valve head and the skirt in the direction of the high temperature fluid channel shall be restricted as much as possible, the valve being fitted in such a manner that, on the opening thereof, the annular projection retracts from the said tapered surface, so that the flow passage in between them shall increase very rapidly and permit the cooling fluid to scavenge the periphery of the valve head at the moment when high temperature fluid is admitted to the cylinder.
 2. A motor as claimed in claim 1, wherein said inlet valve head is provided with a recess on its face directed towards the inside of the skirt, in order to provide inside the valve a peripheric chamber of large dimensions communicating with the inside of the skirt fed with pressurized cooling fluid.
 3. A motor as claimed in claim 1, wherein a by-pass is provided in the cooling fluid feed pipe upstream of the said skirt, this by-pass opening in a peripheric recess provided around the inlet valve seat beneath the said skirt, this recess communicating over the whole of its periphery with the high temperature fluid channel, facing the valve head area not surrounded by the skirt, so that the cooling fluid shall cool the latter area. 